Unnecessary ellipsis between sibling page numbers for rotating pagination

[dmytroyarmak]

Bug description:

In some cases, when using rotation pagination component renders unnecessary ellipsis between sibling page numbers.
For example for:

• page numbers: 7
• current page: 5
• max pages: 3

The result will be (incorrect):

['« Previous', '1', '-...', '4', '+5', '6', '-...',  '7', '» Next']

instead of (correct)

['« Previous', '1', '-...', '4', '+5', '6', '7', '» Next']

The same problem happens on the 3rd page.

Link to minimally-working plunker that reproduces the issue:

http://plnkr.co/edit/Jr28Ft?p=preview

Version of Angular, ng-bootstrap, and Bootstrap:

Angular: 2.0.0

ng-bootstrap: 1.0.0-alpha.18

Bootstrap: 4.0.0-alpha.6

[pkozlowski-opensource]

Sounds like #1166. I had a brief look at your PR at it seems fine. Will do a proper review & merge tomorrow.

Thnx for stepping in and contributing - much appreciated!

[pkozlowski-opensource]

Merged, thnx!